Evaluation of antibacterial activity of copper-based nanomaterials for food packaging applications

The antibacterial activity of a novel nanocomposite film based on polylactic acid film coated by a sol-gel processing with copper nanoparticles (Cu NPs) at different concentrations (0-0.5-1-10-100-500-1000-2000 ppm) was tested against Salmonella enterica serovar Typhimurium, a pathogenic bacterium frequently associated with human salmonellosis outbreaks related to the consumption of contaminated pig meat and products thereof. Antibacterial activity was determined quantitatively using a viable cell count method. The film coated with the sol containing Cu NPs at 500 ppm provided a significant bacterial reduction (1.38±0.55 log cfu/cm2; P<0.05). Data of copper release from the nanocomposite film were matched with bioactivity test.